An all-around image-capturing apparatus capable of capturing an image of subjects all around the image-capturing apparatus (360 degrees) using an all-around image-capturing optical system having a reflection surface having a rotationally symmetrical shape is known (see Patent Literature 1, 2). The all-around image-capturing apparatus collects lights of subject images all around the image-capturing apparatus incident upon the reflection surface of the all-around image-capturing optical system, and captures the subject images using an image-capturing device. As described above, the image captured using the all-around image-capturing optical system is a ring-shaped image showing the subjects all around the image-capturing apparatus (see Patent Literature 3). Such all-around image-capturing apparatus has an advantage in that the image all around the image-capturing apparatus can be captured with the single apparatus. Therefore, in the past, such all-around image-capturing apparatus is mainly used for professional cameras such as a security camera and an endoscope camera.